Page turning mechanism

ABSTRACT

A plurality of pulleys and cables are secured respectively to a plurality of cooperating rotatable vertical wire rods which have horizontal extensions at each end and vertically disposed clear plastic strips connected between the ends for holding and turning pages. The cables are connected to horizontal slidable bars which are controlled by movement of a vertical cam plate, rack and pawl mechanism in one direction to turn individual rods and pages from right to left upon each movement of a first lever. A second lever and linkage and oppositely acting pawl, rack and cam turn the rods and page holders in the reverse direction from left to right. A rapid turning mechanism can successively turn all of the rods back and forth while bypassing the lever and pawl mechanism.

United States Patent [191 Bombardi [111 3,823,638 [451 July 16, 1974 PAGE TURNING MECHANISM Primary Examinew-kawrence R; Franklin [76] Inventor: Aldo L. Bombardi, 202 Smull Ave., Ammey Gddberg North Caldwell, NJ. 07006 [57] R C [22] Wed: 1973 A plurality of pulleys and cables are secured respec- [21] Appl. No.: 322,420 otively to a plurality of cooperating rotatable vertical wire rods which have horizontal extensions at each end and vertically disposed clear plastic strips con- 84/503 nected between the ends for holding and turning 58] Fieid 507 pages. The cables are connected to horizontal slidable bars which are controlled by movement of a vertical cam plate, rack and paw] mechanism in one direction [56] References Cited to turn individual rods and pages from right to left upon each movement of a first lever. A second lever UNITED STATES PATENTS and linkage and oppositely acting pawl, rack and cam 217,473 7/ 1879 Moore 84/503 turn the rods and page holders in the reverse direction Fletcher from left to A rapid turning mechanism can sue. $38; s fi f y cessively turn all of the rods back and forth while by- 3 732 773 5/1973 Bo r rl bardi :I:IIIZIIIIIII: 84/491 ,passmg the h and paw] mechamsm l 12. Claims, 24 Drawing Figures g I t 142 ,4; 12 lo a 4 2 o so a I53 I40 r37 I Z/ 0m 82x lfl O 54 56 rao as 2a film/w g t a I66 #7? 25 kW" N we va4 PATENTEU I 61974 v 3.823.638

SHEET 10? 5 jg l PATENIED JUL 1 s 1914 SHEET 30F 5 PA E JUL 1 s 1914 3, 23 53 SHEET 5 or 5 PAGE TURNING MECHANISM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to mechanical page turning devices and particularly to an improved more reliable efficient page turner which rapidly turns the pages in either direction by direct rotation of vertical rod page holders.

2. Description of the Prior Art A previous device for turning sheets of music or pages of various typesof publications has been described in a copending application by the present inventor now issued as US Pat. No. 3,732,773 on May 15, 1973. In that device, a plurality of vertical rods having horizontal extensions at each end and vertically disposed clear plastic strips connected between the ends for holding pages was rotated from one side to another by biased helical torsion springs secured around each respective rod. Each rod rotated about a separate vertical axis in support bushings and adjacent horizontal ends were spaced vertically with each rod end being held in a slotted latching bracket. Vertical movement of a slidable rack and pawl released each end from the latch so that the spring would cause the rod to swing from right to left while carrying and turning a page. The rods were returned manually to the latched or loaded postion. This device thus relied upon the torsion of each spring to turn the rods and required somewhat critical adjustments of various elements to achieve the necessary continuously repetitive operations. In addition, it could not operate automatically in both directIons.

SUMMARY OF THE INVENTION It is therefore the primary object of the present invention to provide-an automatic page turner of improved reliability and efficiency wherein the vertical rods are turned-by direct positive mechanical rotation of a pulley and cable arrangement and a reversible control mechanism which operates in either direction.

This is achieved by a novel coupling and control mechanism wherein a pulley and cable are secured around each vertical rod page holder. The cables are guided around a second group of idler pulleys and are connected to respective horizontally slidable bars which engage horizontal channels in a stationary vertical guide block. Each bar has a cam follower roller at the end which rides in a vertical cam slot having two offset portions along a vertically movable plate. A first lever controls a first vertically movable pawl which engages successive individual teeth in a rack along one side of the plate to move the plate in one direction and change the horizontal position of the rollers and bars along the cam slot. Movement of the bars then rotates the cables and pulleys to turn the respective individual rods and pages from right to left. A second lever and symmetrical vertical pawl and rack along a second portion of the plate selectively moves the plate, cam slot and bars in the opposite direction to return the rods from left to right into the starting position. A faster operating pulley and cable mechanism bypasses the levers and pawls to provide rapid turning of the rods successively in either direction. The details of the invention and other objects and advantages will become apparent from the following description in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of the novel device showing two groups of page holders with sheets of music of a publication on opposite sides of a base plate;

FIG. 2 is a partial front view with the front base plate removed to show the vertical rods, attached pulleys and cables, vertical cam, pawl, rack and control mechanIsm;

FIGS. 3a and 3b show a partial enlarged isometric view of a pulley and cable about'a rod and a section of rod secured within a pulley;

FIGS. 4a, 4b and 4c show front, side and end views of a pulley support bracket;

FIGS. 5a, 5b and 50 show a front and end view of a typical horizontal bar and roller connected to the back group of rods and an end view of a bar for connection to a rod in the front group; I

FIGS. 6a, 6b and 60 show front, end andside views of an idler pulley and cable tension adjuster;

FIG. 7 is an end view of a typical front and back rod assembly and control mechanism;

' FIGS. 8a, 8b and 8c show front, side and end views of the vertical camplate and rack;'

FIG. 9 is a front isometric view of the guide block for the horizontal bars, vertical cam plate and pawl assemy;

FIG. '10 is an enlarged front view of a pawl assembly;

FIG. 11a and 11b show partial views of the pawl engaging and disengaged from the vertical cam plate rack; and

FIGS. 12a, 12b and show front, end and front assembly views of an alternate embodiment for an idler puller and cable tensioning device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, pages of a publication, such as sheets of music 10 which are to be turned automatically, are supported on a base plate 12, with the front and back covers or unused .outer groups of pages secured in position by adjustable clamps 14, 16 on opposite sides of the base plate. The center fold of the pages is preferably held in position by a resilient central clamp 18. The selected group of pages which are to be turned mechanically are individually inserted between respective pairs of longitudinal clear plastic strips 20 which engage both sides along the full length of each page. Each set of strips is connected in a front and back pairto respective horizontal rod end portions 22 which extend from opposite ends of respective vertical rotatable rods 24. 12 such pairs of strips and rods to accommodate l2-pages are illustrated in this example. A central area 25 at the upper end of the base plate 12 is cut out to provide an area in which the rod ends are turned. The structure of the rods and plastic strips is more fully described in the aforementioned earlier US. Pat; No. 3,732,773 which employs a different drive and control mechanism.

FIG. 2 is a view of the present device with the front base plate cover removed to show the details of the internal mechanism. The vertical rods 24 are rotatably supported on a back base plate 26 by two bushings 28, 30 adjacent opposite ends of the rods. The bushings each have two rows of six holes, one over the other, to provide separate spaced vertical axes about which the individual vrods turn. The rods. are arranged in two groups of six in front and back tiers corresponding with the two rows of holes in the bushings. As shown, the front tier of rods is turned to the left side of the base plate and the back tier to the right. Metal sleeves 32 around the rods at the lower end bushing 30 provide alignment and prevent undesired longitudinal movement of the rods in the downward direction.

The horizontal ends 22 of the rods are all spaced vertically from one another so as to minimize overlap and interference during turning. The rod ends have a generally outward slant at a suitable angle from the base and vertical axis, as shown in FIG. '7, toaccommodate the height of the underlying longitudinal plastic strips which each rest upon the immediately preceding strip when successively turned in the same direction. As shown in FIG. 2, the front row beginning with the rod on the left isturned first during successive movement from right to left, while the reverse direction starts with the rods in the back row on the right.

Secured in the mid-section along each of the rods, at different stepped vertical and horizontally spaced postions, are a plurality of driver pulleys 34, 35 arranged in corresponding front and back rows of six. The back row 35 is also spaced vertically upwardly along the base from the front row 34. A typical pulley is shown in more detail in FIG. 3a. Each pulley is fastened about a respective vertical rod which may have a splined knurled shaft surface 36, as shown in FIG. 3b, to fit tightly within a central bore 38 in the pulley. Each pulley has two annular grooves 40, 42 which respectively accommodate two ends 44, 46 of a twisted strand wire cable. The cable ends are crimped into the grooves at segments approximately 180 apart so that one cable end 44, with FIG. 3a viewed along the bottom of the page, extends horizontally to the right from the lower back end of groove 40 of pulley 34 and the other cable end 46 extends in the same direction from groove 42 at the top front of the pulley. Tension on the front cable portion 46 will thus pull and rotate the pulley and rod clockwise or to the right, as indicated by arrow 48, while tension on the lower back portion 44 will rotate the pulley and rod counterclockwise or to the left, as shown by arrow 50.

The pulleys in each group of six are successively spaced in equal steps upwardly from left to right along each respective adjacent rod. The pulleys are secured in two groups on-brackets 52, 54 which respectively support the pulleys associated with the front and back tier of rods. Bracket 52 is raised from the base plate to support the front tier of pulleys. Bracket 54 is disposed vertically toward the upper end along the rods with respect to bracket 52. FIGS. 4a, 4b and 4c illustrate front, side and end views of bracket 54 in further detail. The upper, flat side of each respective pulley abuts a corresponding end flange 56 on bracket 54 and similar flanges on bracket 52. Flanges 56 have holes 57 to accommodate the rods and prevent upward movement of the pulleys and rods to aid in maintaining the longitudinal position of the rods.

The opposite endsof the cables from pulleys 34, 35 extend horizontally in different lengths to a plurality of equally vertically spaced horizontally movable bars 58, each associated with a respective pulley and rod. The

lower group of six bars is connected by the'cables to the front lower tier of pulley 34 on bracket 52 and the upper group of bars is connected to the upper rear pulleys on bracket 54. FIGS. a, 5b and 5c show a front and end view of a bar associated with a rear pulley and an end view of a bar connected to a front tier pulley. Each bar has a slot 60 in the left end and a screw 62 which accommodate and clamp a section of the cable so that horizontal movement of the bar pulls the cable and pulley. The left end 64 of each front tier bar is curved forwardly to meet the level of the cable'from the front tier pulleys. I g

Secured to the base plate in an aligned vertical row along the central area of the bars 58 are a plurality of idler pulleys 66 rotatably mounted on cable tension adjuster brackets 68, shown in further detail in top, end

and side views in FIGS. 61 1, 6b and 6c. The extending portion of' each cable fits around the groove in each idler pulley, so that the front cable portion 46 from a pulley 34, 35 is clamped in slot 60 of each bar 58 and is then looped over the front of idler pulley 66 and under the back to return to the other cable end 44 secured to the back of pulley 34, 35. Each idler pulley 66 is supported in a freely rotatable angled vertical position at the end of a tension adjuster bracket 68. A horizontal slot 70 and screw 72 secured to the base plate permit horizontal movement of the bracket to take up any, slack in the cable and maintain a suitable tension therein. The idler pulley thus guides and is driven by the movement of the cable. The group of brackets 68 and idler pulleys 66 for the front tier of bars and rods are also raised above the level of the back tier brackets to meet the cables from the respective front tier driver pulleys. g

FIG. 7 shows an end view of a typical front and back rod, driver pulley, cable, bar and idler pulley assembly.

Mounted at the other end of each bar 58 is a freely rotatable cam follower or roller.74 which is adapted to engage a vertical slot 76 in a vertically movable cam plate 78 shown more clearly in front, side and end views in FIGS. 8a, 8b and 80. Behind the cam plate along one side is secured a rack 80 having a plurality of teeth 82 extending from the side. Cam plate 78 is slidably mounted over a stationary guide block 84,.as shown in a top isometric view in FIG. 9, which is secured on baseplate 26. The guide block includes a plurality of horizontal channels 86 which receive and guide the movement of horizontal bars 58 and a vertical channel 88 which accommodates and guides toothed rack 80 secured to cam plate 78. The rollers 74 of bars 58 engage the vertical slot 76 of the cam plate.

The vertical slot includes two horizontally offset por-' tions 90, 92 and curved connecting passage 94 so that upward movement of the cam plate along block 84 causes the rollers to'successively move from the upper right slot 92 through passage 94 into the lower left slot thus causing respective bars, cables, pulleys and .rods to move from right to left. Reverse movement of is disposed along the upper end of rack 80 and is connected by a spring 103 to the lower pawl. The paiil/l assemblies 96, 102 are positioned adjacent longitudinal openings 104, 106 along vertical bars 108, 110, 112 so that the pawls 114, 116 extend through the openings to engage teeth 82 of rack 80. The pawl assembly 96 is connected by a vertical rod 118 to a horizontal control lever 120 having an extension 122 with a plate 123 which normally extend horizontally'from the right side of base plate 12. Downward pressure on plate 123 and levers 122 and 120, such'as by a finger of a person desiring to turn pages, pulls rod 118 and paw] 114 in the 'down direction. The pawl, which is normally maintained in a disengaged position by spring 103 and bar 110, as shown in FIG. 11b, is then pulled into opening 104 to pivot into engagement with a tooth 82 on rack 80, as shown in FIG. 1la. This moves the rack downwardly adistance equal to the spacing between teeth. The rack in turn moves cam plate 78 and slot 76 down to cause a roller 74 to move to the'right along with a bar 58 and thus turns a pulley 34, 35, cables 44, 46 and rod 24 from left to right.

Adjustable limit stops 124, 125 are positioned above and below. lever 120 at the proper spacing to limit the tween corresponding points on adjacent teeth may be plate 26. Vertical plates 137, 139 are mounted on opposite ends of the rod to facilitate horizontal movement of the rod by hand. Also mounted on the rod is a pointer 140 to indicate successive page numbers on a graduated scale 142 secured in the central area on the upper end of the base plate. At each end of the scale are additional fixed vertical plates 144, 146 which are used incooperation with the plates 137, 139 on the slidable rod 131 to manually move the rod to the left or right to rapidly turn the rods and pages.

A control cable 148 is secured in a slot 150 under a screw 152 in a bracket 154 mounted on plate 139 so that the cable 148 moves back and forth with rod 131. Cable 148 passes around idler pulleys 156, 158 secured on'the baseplate and is fastened at the upper end of cam plate 78 by a hook 160 and screw 162. The cable also passes in the other direction around idler pulley 164 at the upper end of the base plate to pulleys 166 and 168 at'the lower end and connects to the lower end of cam'plate 78 by a second hook 170 and screw 172. The position of hook 170 is adjustable to maintain a desired tension in cable 148. The page turning rods 24 may then be turned rapidly and continuously without the leverand pawl mechanisms by pushing rod 131 to A inch with the teeth being A; inch in height. The pawl assembly includes a lever spring 126 which urges the pawl into engagement with the teeth. When lever'122- is released, spring l03pulls the pawl assembly back into the normally disengaged position, with the pawl pivoting counterclockwise and cocking lever spring 126 for the-next downward movement. Bar 110 also normally prevents pawl 116 at the other end from engaging teeth when not properly actuated in the reverse direction and spring 103 maintains the pawls and levers in a neutral position.

The reverse operation to move rack 80 in the upward direction and turn pages from right to left is initiated by pressing down on control lever 128 and the lower left side of the base plate. This pulls vertical connecting rod 130 downwardly, pivoting an L-shaped connecting lever 132 counterclockwise andpulling horizontal rod 134' to the left. A second L-shaped lever 136 is also pivoted counterclockwise to pull vertical ,rod 138 and pawl assembly 102 upwardly. Pawl 116 then pivots through opening 106 into engagement with an upper tooth 82 in rack 80 to move cam plate 78 upwardly. This moves a roller 74 and bar 58 to the left and the connected driver pulley, cable and rod turn to the left carrying a page therewith. Successive movementsof levers 122 or 128 on either side cause successive movements of the rods in a respective direction until all rods and pages are turned to one side of the base plate. In some applications a foot operated pedal may replace the hand operated levers, if so desired. In addition, various components such as the pawl assemblies, toothed rack and guide block may be made of suitable plastics material.

At certain times, it may be desirable to quickly turn all or some of thepages in either direction withone continuous rapid movement without turning each individual page intermittently with the control levers. For this purpose, a rapid turning mechanism is provided which bypasses the rack and pawl mechanism. This is accomplished by a horizontally movable control rod 131 slidably mounted in two support bushings 133, 135 secured at opposite sideson the upper end of the base the left or right. Movement to the left is accomplished by grasping fixed vertical plate 146 and plate 139 on the right side I of slidable rod 131 and firmly pushing plate 139 and rod 131 from right to left toward plate 146. Cable 148 secured to plate 139 on rod 131 is thus likewise moved to the left and pulls cam plate 74 in the upward direction to move rollers 74 and bars 58 to the left and turn the driver pulleys, cables and rods to the left in rapid succession until all or a desired number of the pages are turned. By moving the fixed pointer on rod 131 to a particular number setting on indicator 142 the continuous rotation of rods 24 may be stopped at a desired page number or position. Return movement from left toright is accomplished by grasping end plates 137 and 144 and pushing rod 131 to the right. Cable 148 is then pulled to the right and in turn pulls hook and cam plate 74 downwardly, thus moving rollers 74 and bars 58 to the right while turning pulleys 34, 35, cables 44, 46 and successive rods 24 and pages to the right. The control levers 120, 128 and paw] assembly mechanisms 96, 102 are thus bypassed with the bar 110 and spring 103 holding the pawls out of engagement with the teeth as cam plate 78 and rack 80 move up and down. The rapid turning mechanism may also be located at the lower end of the base plate if so desired.

In another variation, shown in FIGS. 12a, 12b and 12c, the idler pulley 66 and cable tension adjuster bracket 68 may be replaced by an alternate self adjusting embodiment including an idler pulley 174 supported in a bracket 176 on one end of a rod 178. The end of the cable 44, 46 from pulleys 34, 35 on rods 24 fits around idler pulley 174. A plurality of rods 178 are slidably mounted within a plastic block 180 secured on base plate 26 behind the mid-section of bars 58. At the other end of the rod 178 are a head 182, a compression spring 184 around the rod and a locking washer 186 between the spring 184'and block 180. Tension in the cable is then maintained by spring pressure against the head 182 of rod 178 with the other end of the spring pressing against washer 186. The spring causes the washer to tilt at a slight angle to hold rod 178 in place against block 180.Tension is thus. maintained when out departing from the scope of the invention as set forthin the appended claims.

What is claimed is: l. A page turning device comprising a base plate for supporting a publication having a plurality of pages; a plurality of vertically disposed wire rods pivotally mounted on a central area of said base plate, each rod having opposite'horizontally extending ends vertically spaced from each adjacent rod end; a plurality of wire rod supportsspaced along said rods on said base plate, each rod being rotatable about'aseparate vertical axis through said supdrawing said cables to rotate said pulleys and turn said rods and page holding strips.

3. The device of claim 2 wherein said means for moving said cam plate includes a vertically disposed toothed rack secured along one side of said cam plate, a pair of opposing vertically disposed pawls positioned adjacent said rack for engagement therewith, means for normally holding said pawls out of engagement with said rack, and a pair of intermittently-operable levers connected to respective said pawls, movement of the first said lever causing the first said pawl to engage a tooth of said rack to move said cam plate downwardly a predetermined fixed distance between adjacent teeth and move a respective bar and cable and turn a respective pulleyand rod from left to right,movement of the second said lever causing the second said pawl to engage a tooth of said rack to move said cam plate upports, a group of said wire rods being spaced horizontally in a common plane through said supports;

plurality of vertically extending thin flexible page holding strips connected respectively between said opposite horizontally extending ends of each rod and engageable with the length of a page;

a plurality of pulleys coaxially secured respectively on each vertical rod for rotation therewith, each pulley being spaced in vertical steps along each respective rod from each adjacent pulley, each pulley of a group of said pulleys being spaced in successive horizontal steps on respective adjacent vertical rods in said group of rods;

a plurality of horizontally disposed vertically spaced wire cables secured respectively to each pulley; rotatable support means for guiding each respective said cable in alternate-directions along a looped horizontal path, the horizontal length of each said wardly said predetermined distance and move a respective bar andcable and turn a respective pulley and rod from right to left, successive movements of each lever engaging'successive teeth and moving successive rods in a selective alternate direction.

4. The device of claim 3 wherein said means for moving said cam plate includes an additional rapid continuou's'turning mechanism having a control cable connected to opposite ends of said cam plate, a plurality of pulleys rotatably secured on said base plate for guiding cable varying insteps in accordance with the distance between each said rotatable support means and each said pulley on each said rod in said group of pulleys and rods; and control means for drawing said cables and rotating said horizontally and vertically spaced pulleys on respective rods successively in selective alternate directions so that each of said cables secured to each of said pulleys on each of said rods turns each of said rods and page holding strips from one side of said base plate to the other. 2. The device of claim 1 wherein said control means includes a plurality of vertically spaced horizontally slidable bars connected respectively to each cable to draw said cables in alternate directions along said horiv zontal path, a vertically slidable cam plate having a vertically disposed cam slot, said cam slotincluding upper and lower horizontally displaced vertical portions and a central connecting portion, coupling means on each said bar engaging said slot to cause horizontal movement of said bars upon vertical movement of said cam i said pawls to normally maintain said said control cable, and a slidable rod connected to said control cable'to draw said control cable and cam plate in selective alternate directions to successively move said bars and cables and turn the respective said pulleys and rods.

1 5. The device of claim 4 including means for indicating the number of rods in an intermediate turned position of said rapid turning mechanism.

includes rollers rotatably mounted on said bars.

7. The device of claim 3 whereinsaid rotatable support means includes a plurality of idler pulleys secured on said base plate and rotatably supporting each respective cable. r

8. The device of claim 7 wherein said rods, pulleys on said rods, cables, bars and idler pulleys are arranged in two tier groups, one behind the other.

9. The device of claim 8 including means for limiting the movement of said levers to move said pawls said predetermined distance.

10. The device of claim 8 wherein said rod supports include means for limiting the vertical movement of said rods.

, 11. The device of claim 8 including a guide block having horizontal channels for said plurality of horizontal bars, a first vertical channel for said toothed rack, a second vertical channel for said pair of opposed pawls, and a vertical bar between said pawls and toothedrack and resilient means connected between pawls out of engagement with said teeth.

12. The device of claim 8 including tension adjusting means connected to each said idler pulley for applying adjustable tension to each said cable secured to said pulleys on said rods. 

1. A page turning device comprising a base plate for supporting a publication having a plurality of pages; a plurality of vertically disposed wire rods pivotally mounted on a central area of said base plate, each rod having opposite horizontally extending ends vertically spaced from each adjacent rod end; a plurality of wire rod supports spaced along said rods on said base plate, each rod being rotatable about a separate vertical axis through said supports, a group of said wire rods being spaced horizontally in a common plane through said supports; a plurality of vertically extending thin flexible page holding strips connected respectively between said opposite horizontally extending ends of each rod and engageable with the length of a page; a plurality of pulleys coaxially secured respectively on each vertical rod for rotation therewith, each pulley being spaced in vertical steps along each respective rod from each adjacent pulley, each pulley of a group of said pulleys being spaced in successive horizontal steps on respective adjacent vertical rods in said group of rods; a plurality of horizontally disposed vertically spaced wire cables secured respectively to each pulley; rotatable support means for guiding each respective said cable in alternate directions along a looped horizontal path, the horizontal length of each said cable varying in steps in accordance with the distance between each said rotatable support means and each said pullEy on each said rod in said group of pulleys and rods; and control means for drawing said cables and rotating said horizontally and vertically spaced pulleys on respective rods successively in selective alternate directions so that each of said cables secured to each of said pulleys on each of said rods turns each of said rods and page holding strips from one side of said base plate to the other.
 2. The device of claim 1 wherein said control means includes a plurality of vertically spaced horizontally slidable bars connected respectively to each cable to draw said cables in alternate directions along said horizontal path, a vertically slidable cam plate having a vertically disposed cam slot, said cam slot including upper and lower horizontally displaced vertical portions and a central connecting portion, coupling means on each said bar engaging said slot to cause horizontal movement of said bars upon vertical movement of said cam plate and slot, and means for moving said cam plate in selective alternate vertical directions, said cam slot moving said coupling means horizontally between said upper and lower portions and successively moving said bars in a corresponding horizontal direction, said bars drawing said cables to rotate said pulleys and turn said rods and page holding strips.
 3. The device of claim 2 wherein said means for moving said cam plate includes a vertically disposed toothed rack secured along one side of said cam plate, a pair of opposing vertically disposed pawls positioned adjacent said rack for engagement therewith, means for normally holding said pawls out of engagement with said rack, and a pair of intermittently operable levers connected to respective said pawls, movement of the first said lever causing the first said pawl to engage a tooth of said rack to move said cam plate downwardly a predetermined fixed distance between adjacent teeth and move a respective bar and cable and turn a respective pulley and rod from left to right, movement of the second said lever causing the second said pawl to engage a tooth of said rack to move said cam plate upwardly said predetermined distance and move a respective bar and cable and turn a respective pulley and rod from right to left, successive movements of each lever engaging successive teeth and moving successive rods in a selective alternate direction.
 4. The device of claim 3 wherein said means for moving said cam plate includes an additional rapid continuous turning mechanism having a control cable connected to opposite ends of said cam plate, a plurality of pulleys rotatably secured on said base plate for guiding said control cable, and a slidable rod connected to said control cable to draw said control cable and cam plate in selective alternate directions to successively move said bars and cables and turn the respective said pulleys and rods.
 5. The device of claim 4 including means for indicating the number of rods in an intermediate turned position of said rapid turning mechanism.
 6. The device of claim 3 wherein said coupling means includes rollers rotatably mounted on said bars.
 7. The device of claim 3 wherein said rotatable support means includes a plurality of idler pulleys secured on said base plate and rotatably supporting each respective cable.
 8. The device of claim 7 wherein said rods, pulleys on said rods, cables, bars and idler pulleys are arranged in two tier groups, one behind the other.
 9. The device of claim 8 including means for limiting the movement of said levers to move said pawls said predetermined distance.
 10. The device of claim 8 wherein said rod supports include means for limiting the vertical movement of said rods.
 11. The device of claim 8 including a guide block having horizontal channels for said plurality of horizontal bars, a first vertical channel for said toothed rack, a second vertical channel for said pair of opposed pawls, and a vertical bar between said pawls and toothed rack and resilient means connected between said pawls to normalLy maintain said pawls out of engagement with said teeth.
 12. The device of claim 8 including tension adjusting means connected to each said idler pulley for applying adjustable tension to each said cable secured to said pulleys on said rods. 